[llvm] r371107 - [X86] Enable BuildSDIVPow2 for i16.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Thu Sep  5 11:49:52 2019
New Revision: 371107

URL: http://llvm.org/viewvc/llvm-project?rev=371107&view=rev
Log:
[X86] Enable BuildSDIVPow2 for i16.

We're able to use a 32-bit ADD and CMOV here and should work
well with our other i16->i32 promotion optimizations.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/combine-sdiv.ll
    llvm/trunk/test/CodeGen/X86/combine-srem.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=371107&r1=371106&r2=371107&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Sep  5 11:49:52 2019
@@ -20098,8 +20098,9 @@ X86TargetLowering::BuildSDIVPow2(SDNode
 
   // fold (sdiv X, pow2)
   EVT VT = N->getValueType(0);
-  // FIXME: Support i8/i16.
-  if ((VT != MVT::i32 && !(Subtarget.is64Bit() && VT == MVT::i64)))
+  // FIXME: Support i8.
+  if (VT != MVT::i16 && VT != MVT::i32 &&
+      !(Subtarget.is64Bit() && VT == MVT::i64))
     return SDValue();
 
   unsigned Lg2 = Divisor.countTrailingZeros();

Modified: llvm/trunk/test/CodeGen/X86/combine-sdiv.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/combine-sdiv.ll?rev=371107&r1=371106&r2=371107&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/combine-sdiv.ll (original)
+++ llvm/trunk/test/CodeGen/X86/combine-sdiv.ll Thu Sep  5 11:49:52 2019
@@ -3168,10 +3168,10 @@ define i8 @combine_i8_sdiv_negpow2(i8 %x
 define i16 @combine_i16_sdiv_pow2(i16 %x) {
 ; CHECK-LABEL: combine_i16_sdiv_pow2:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movswl %di, %eax
-; CHECK-NEXT:    shrl $27, %eax
-; CHECK-NEXT:    andl $15, %eax
-; CHECK-NEXT:    addl %edi, %eax
+; CHECK-NEXT:    # kill: def $edi killed $edi def $rdi
+; CHECK-NEXT:    leal 15(%rdi), %eax
+; CHECK-NEXT:    testw %di, %di
+; CHECK-NEXT:    cmovnsl %edi, %eax
 ; CHECK-NEXT:    cwtl
 ; CHECK-NEXT:    shrl $4, %eax
 ; CHECK-NEXT:    # kill: def $ax killed $ax killed $eax
@@ -3183,10 +3183,10 @@ define i16 @combine_i16_sdiv_pow2(i16 %x
 define i16 @combine_i16_sdiv_negpow2(i16 %x) {
 ; CHECK-LABEL: combine_i16_sdiv_negpow2:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    movswl %di, %eax
-; CHECK-NEXT:    shrl $23, %eax
-; CHECK-NEXT:    movzbl %al, %eax
-; CHECK-NEXT:    addl %edi, %eax
+; CHECK-NEXT:    # kill: def $edi killed $edi def $rdi
+; CHECK-NEXT:    leal 255(%rdi), %eax
+; CHECK-NEXT:    testw %di, %di
+; CHECK-NEXT:    cmovnsl %edi, %eax
 ; CHECK-NEXT:    cwtl
 ; CHECK-NEXT:    sarl $8, %eax
 ; CHECK-NEXT:    negl %eax

Modified: llvm/trunk/test/CodeGen/X86/combine-srem.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/combine-srem.ll?rev=371107&r1=371106&r2=371107&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/combine-srem.ll (original)
+++ llvm/trunk/test/CodeGen/X86/combine-srem.ll Thu Sep  5 11:49:52 2019
@@ -480,13 +480,12 @@ define i16 @combine_i16_srem_pow2(i16 %x
 ; CHECK-LABEL: combine_i16_srem_pow2:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    movswl %ax, %ecx
-; CHECK-NEXT:    shrl $27, %ecx
-; CHECK-NEXT:    andl $15, %ecx
-; CHECK-NEXT:    addl %edi, %ecx
+; CHECK-NEXT:    leal 15(%rax), %ecx
+; CHECK-NEXT:    testw %ax, %ax
+; CHECK-NEXT:    cmovnsl %edi, %ecx
 ; CHECK-NEXT:    andl $-16, %ecx
 ; CHECK-NEXT:    subl %ecx, %eax
-; CHECK-NEXT:    # kill: def $ax killed $ax killed $eax
+; CHECK-NEXT:    # kill: def $ax killed $ax killed $rax
 ; CHECK-NEXT:    retq
   %1 = srem i16 %x, 16
   ret i16 %1
@@ -496,13 +495,12 @@ define i16 @combine_i16_srem_negpow2(i16
 ; CHECK-LABEL: combine_i16_srem_negpow2:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    movl %edi, %eax
-; CHECK-NEXT:    movswl %ax, %ecx
-; CHECK-NEXT:    shrl $23, %ecx
-; CHECK-NEXT:    movzbl %cl, %ecx
-; CHECK-NEXT:    addl %edi, %ecx
+; CHECK-NEXT:    leal 255(%rax), %ecx
+; CHECK-NEXT:    testw %ax, %ax
+; CHECK-NEXT:    cmovnsl %edi, %ecx
 ; CHECK-NEXT:    andl $-256, %ecx
 ; CHECK-NEXT:    subl %ecx, %eax
-; CHECK-NEXT:    # kill: def $ax killed $ax killed $eax
+; CHECK-NEXT:    # kill: def $ax killed $ax killed $rax
 ; CHECK-NEXT:    retq
   %1 = srem i16 %x, -256
   ret i16 %1